The present invention relates to a method for removing a metallic deposit placed on a surface in an enclosure.
A method for removing a metallic deposit on a surface of an enclosure, known in the state of the art, comprises the following steps:                a) a step of oxidizing the metallic deposit;        b) a step of injecting chemical species adapted to volatilize the oxidized metallic deposit, said step b) being implemented during at least a part of step a).        
However, such a removal method is not satisfactory.
In fact, the chemical species adapted to volatilize the oxidized metallic deposit can also react with the metallic deposit before the oxidation of the latter. Step a) is thereby blocked.
Thus, the reaction of the chemical species with the metallic deposit interferes with the removal method, and above all adversely affects its effectiveness.
In particular, this is the case when the removal method is carried out in order to remove a deposit of copper (Cu) on a surface in an enclosure. Step a) generally comprises the introduction of gaseous oxygen or gaseous ozone. The chemical species adapted to volatilize the copper oxide comprise hexafluoroacetylacetone (hfacH). When it is injected into the enclosure, the chemical species hfacH also reacts with the copper before the latter is oxidized. The oxidation reaction is then blocked.
The subject of the present invention is therefore to propose a method for removing a metallic deposit making it possible to limit the parasitic reactions capable of blocking said method.
A first application of the invention relates to cleaning off metallic residues deposited on the inner walls of a deposition chamber.
Another application of the invention relates to the manufacture of printed circuits, and more particularly the etching of metallic layers used in particular for filling vias, which are metalized holes allowing the electrical connection between several layers of a printed circuit.
Conventionally, the vias are filled in excess with a metal such as copper, so as to ensure a satisfactory filling of the vias. The excess metal is removed by a step of chemical mechanical etching. A barrier layer is disposed between the substrate of the printed circuit and the layer of metallic deposit, in order to control the thickness of the etching. The chemical mechanical etching step requires the use of barrier layers so as to ensure a very precise control of the method and moreover requires subsequent operations of cleaning the etched surface, which is complex and expensive.
Another subject of the invention is to propose a method for manufacturing metalized vias that is simplified and less expensive.